Abrasive carrier for processing articles



Patented Dec. 19, 1950 UNITED STATES ABRASIVE CARRIER FOR PROCESSINGARTICLES Joseph Lupo, Mount Vernon, Y.

No Drawing. Application July 24, 1948,

Serial No. 40,620

1 Claim.

This invention relates to the processing of articles for removing therough surfaces produced in the manufacture thereof and to impart theretoa smooth lustrous finish.

The invention has in view an abrasive carrier having the ingredientsrequired for the abrasive operation applied to the surface thereof.

Another object of the invention is to provide a moisture containingcarrier which retains the carrier and the abrasive in a moist or dampcondition to thereby produce an effective abrasive action on thearticles when rolled or tumbled therewith in a tumbling barrel or thelike.

Another object of the invention is to provide a porous fibrous carrierhaving a viscous coating applied thereto in covering relation with thepores in the carrier for retaining liquid in the pores and which coatingforms a base for bonding the abrasive to the carrier.

Still another object of the invention is the provision of a carrier ofsaid character which is adapted for cutting down, burnishing andpolishing both hard and soft metallic and plastic artic les whichrequires less abrasive material than heretofore employed in thepolishing of metal and plastic articles and which does not create dustduring the tumbling operation, while eliminating scratching and pittingof the articles and provides an increased abrasive surface so. as tolessen the time required to process the articles.

Still another object of the invention is the provision of a carrierwhich eliminates the necessity of employing sawdust, wood chips, woodenpegs, bone or ivory pellets so as to render it unnecessary to pack orfill openings or recesses in the articles which must be done whenemploying sawdust, wood chips and the like in order to prevent the samefrom becoming packed in the openings or recesses.

In producing the abrasive material corn cob granules are utilized as thecarrier which are cellular in structure and adapted to absorb liquidsuch as water, kerosene, lubricating oil and the like and to retain theliquid in the pores thereof so that the carrier remains in a moistcondition for an extended period of time. The carriers are moistenedwith a liquid depending upon the nature of the processing operation andafter the liquid has been absorbed by the carrier, the carrier is thentreated with a viscous bonding agent such as liquid collodion or liquidsodium silicate to provide a self-hardening coating on the outersurfaces of the granules so as to cover the pores of the granules andprovide a base for bonding the abrasive to the carrier. When the bondingagent is still in a wet or tacky condition on the outer surfaces of thecorn cob granules powdered abrasive is applied thereto to embed the sametherein and to form an abrasive surface covering the coating. Alubricating vehicle is then applied to the treated corn cob granuleswhich covers the. abrasive with a thin film thereof and effectivelyseals the liquid contained in the cells thereof.

Produced in this manner the carrier holds on the outer surfaces thereofall of the ingredients required in the processing operation. Inprocessing the articles the same are tumbled with the carrier to effecta cutting down or deburring of the rough surfaces produced by themanufacture thereof, The tumbling is repeated with a carrier having afiner grade of abrasive to effect a smoothening oi the surfaces of thearticles and finally the articles are tumbled with a carrier having anextremely light polishing powder to effect a burnishing and polishing ofthe exterior of the surface of the articles. The action of the liquid onthe corn cob granules together with the deposit of the abrasiveingredients thereon, pro.- duce a carrier without sharp edges or ofrounded formation which eliminates pitting of the articles.

In carrying out the foregoing tumbling operations the articles to befinished are placed in a tumbling barrel or the like and are embedded inor substantially covered with the carrier to which the abrasive andlubricating vehicles have been applied as hereinbefore described. Aftera short period of tumbling the articles become coated with a thin filmof the lubricating vehicle. Further tumbling causes some of the abrasiveto wear off of the corn cob granules and to adhere to the coating on thearticles. Both the articles and the carrier being coated with theabrasive will produce an abrasive action on the articles by the tumblingof the articles with the carrier so as to remove the rough outersurfaces and apply a smooth, lustrous finish free from scratches andpitting. The moisture in the carrier retains the corn cob granulestogether with the bonding agent and abrasive in a damp condition whichfacilitates the cutting action of the abrasive on the surfaces of thearticles.

The carrier is prepared for the first or cutting down operation bymoistening the corn cob granules with a liquid in the proportion ofapproximately eighteen or twenty pounds of granules to one quart ofliquid such as water or kerosene. This may be done by tumbling the corncob granules with the water or kerosene sprinkled thereover in atumbling barrel or the like for approximately ten minutes. The cellularstructure of the corn cob expands by the action of the liquid whichtakes up or absorbs the same. When employing pumice as the abrasive, thecorn cob granules are preferably treated with water while the corn cobgranules are preferably treated with kerosene when using emery as theabrasive. Approximately three-quarters of a pound of liquid collodion,liquid sodium silicate or equivalent gelatinous bonding agent is thenadded to the moistened corn cob granules which are thoroughly coatedtherewithby tumbling the same for approximately ten minutes, after whichtwo pounds of pumice, emery or an equivalent abrasive is applied to thecoated granules when the coatin is still in a wet or tacky condition sothat the abrasive adheres to and covers the coating. In the event that aheavier coating of abrasive is desired a few ounces of water may beadded after which a few ounces of pumice may be tumbled with the treatedcorn cob granules. lubricating vehicle is then applied to the aforesaidproportion of corn cob granules consisting of approximately two ouncesof oleic acid, four ounces of tallow and two ounces of glycerin which isthoroughly coated therewith by tumbling the same for approximatelyone-half hour. The lubricating vehicle completely covers the pumice andseals the cellular structure of the granules so as to maintain themoistened condition of the granules for a considerable period of time.

The aforesaid proportion of treated corn cob granules may then beutilized to process metallic or plastic articles in the proportion oftwo parts by volume of carrier to one part by volume of the articleswhich are distributed throughout and embedded with the carrier in thetumbling operation. The tumbling of the articles with the carriercreates sufiicient friction to heat the carrier so that the lubricatingvehicle coats the outer faces of the articles with a thin film thereof,after which some of the abrasive works loose from the coating whichadheres to the film covered articles. The moisture in the carriermaintains the abrasive in a moistened condition to produce an effectivecutting down or abrading operation.

For the second or smoothening operation, the carrier is prepared in asimilar manner to that described in connection with th preparation ofthe same for the first or cutting down operation but in place of thegranules being expanded by the action of water, the same are treatedwith light lubricating oil which is absorbed or taken up by thegranules. A finer abrasive is employed in connection with the secondoperation and the same may consist of polishing powders such as aluminumoxide, precipitated chalk or the like. The abrasive is applied to thegranules coated with the self-hardening bonding agent in substantiallythe same proportions as described in connection with the first operationand thereafter the abrasive coated granules are treated with alubricating vehicle consisting of approximately two ounces of oleicacid, four ounces of tallow and two ounces of glycerin. The carrierprepared as aforesaid is utilized to process metallic articles in theroportion of approximately two parts by volume of carrier to one part byvolume of the articles. The tumbling operation similarly coats thearticles being tumbled with a thin film of the lubricating vehicle afterwhich some of the abrasive works loose from the carrier and adheres tothe film covered articles. The liquid absorbed by the carrier maintainsthe abrasive together with the corn cob granules in a moistenedcondition and since the abrasive is relatively mild the same effects asmoothening of the exterior surfaces of the articles.

For the third or polishing operation the carrier is prepared in asimilar manner but instead of the abrasive employed in connection withthe first and second operations, an extremely light precipitated chalk,Paris white, rouge, crocus or fine polishing powder is utilized which isbonded to the corn cob granules in a manner similar to that hereinbeforedescribed.

What is claimed is:

An abrasive carrier for processing articles including corn cob granulesexpanded by water and containing water in the cells thereof, a powderedabrasive, and a coating of sodium silicate bonding the abrasive to thegranules and forming a covering over the cells of the granules.

JOSEPH LUPO.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date Re. 21,432 Lupo Apr. 23, 1940224,078 Copeland Feb. 3, 1880 2,191,803 Oesterle et al Feb. 2'7, 19402,318,578 Malz May 11, was 2,328,998 Radford Sept. 7, 1943

